scholarly journals Anti-Reflection Coatings on 3D-Printed Components

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1519
Author(s):  
John Canning ◽  
Caspar Clark ◽  
Monica Dayao ◽  
Daniel de LaMela ◽  
Michael Logozzo ◽  
...  
Keyword(s):  
Experimental Error ◽  
Lower Cost ◽  
Film Deposition ◽  
Refractive Indices ◽  
Fresnel Reflection ◽  
Shore Hardness ◽  
Optical Components ◽  
3D Printed ◽  
Surface Scatter ◽  
Layer Coating

The use of anti-reflection coatings on 3D-printed components to reduce both Fresnel reflections and scattering is explored. Two similar photo-initiated acrylic commercial material structures, known as Standard Clear (SC: T~60% @ λ = 800 nm) and VeroClear (VC: T~90% @ λ = 800 nm), used specifically for optical components, are examined. The refractive indices for slab samples~(5 × 5 × 0.7) cm are measured at λ = 650 nm and averaged over the slab area: n(SC)~(1.49 ± 0.04) and n(VC)~(1.42 ± 0.03). Within experimental error, novel Shore D mapping is used to show hardness distribution across the surface flats, with VC slightly harder than SC, where VC = 85.9 ± 0.3 and SC = 84.4 ± 1.3, indicating uniform hardness. A TiO2/MgF2 anti-reflection twin-layer coating is deposited onto one side of an unpolished SC slab and binds well, passing standard peeling and humidity tests. Shore hardness increases to SCCOATED = 87.5 ± 1.5. It is found to reduce the measured Fresnel reflection and surface scatter by~65% without requiring major polishing, paving the way for lower-cost high-quality optics. The demonstration of successful anti-reflection coatings will benefit all 3D-printed component finishes, permitting viable film deposition more broadly.

Self-Assembly Optical Components

2003 ◽  
Vol 771 ◽  
Author(s):  
Pavel I. Lazarev ◽  
Michael V. Paukshto ◽  
Elena N. Sidorenko
Keyword(s):  
Optical Properties ◽  
Self Assembly ◽  
Crystalline State ◽  
Liquid Crystalline ◽  
Film Deposition ◽  
X Ray Diffraction ◽  
Optical Components ◽  
Crystal Film ◽  
Solid Film ◽  
Thin Crystal

AbstractWe report a new method of Thin Crystal Film deposition. In the present paper we describe the method of crystallization, structure, and optical properties of Bisbenzimidazo[2,1-a:1',2',b']anthra[2,1,9-def:6,5,10-d'e'f']-diisoquinoline-6,9-dion (mixture with cis-isomer) (abbreviated DBI PTCA) sulfonation product. The Thin Crystal Film has a thickness of 200-1000 nm, with anisotropic optical properties such as refraction and absorption indices. X-ray diffraction data evidences a lyotropic liquid crystalline state in liquid phase and crystalline state in solid film. Anisotropic optical properties of the film make it useful in optical devices, e.g. liquid crystal displays.

Fresnel reflection in optical components and detectors for the terahertz frequency band

2007 ◽  
Vol 50 (4) ◽  
pp. 524-529 ◽  
Author(s):  
V. V. Gerasimov ◽  
B. A. Knyazev ◽  
P. D. Rudych ◽  
V. S. Cherkassky
Keyword(s):  
Frequency Band ◽  
Terahertz Frequency ◽  
Fresnel Reflection ◽  
Optical Components

scholarly journals Surface Preparation and Treatment for Large-Scale 3D-Printed Composite Tooling Coating Adhesion

Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 457 ◽  
Author(s):  
Philipp Sauerbier ◽  
James Anderson ◽  
Douglas Gardner
Keyword(s):  
Additive Manufacturing ◽  
Large Scale ◽  
Lower Cost ◽  
Numerical Control ◽  
Fused Deposition Modelling ◽  
Filler Materials ◽  
Coating Adhesion ◽  
Fused Deposition ◽  
Composite Tooling ◽  
3D Printed

Recent advances in large-scale thermoplastic additive manufacturing (AM), using fused deposition modelling (FDM), have shown that the technology can effectively produce large aerospace tools with common feed stocks, costing 2.3 $/kg, such as a 20% carbon-filled acrylonitrile butadiene styrene (ABS). Large-scale additive manufacturing machines have build-volumes in the range of cubic meters and use commercially available pellet feedstock thermoplastics, which are significantly cheaper (5–10 $/kg) than the filament feedstocks for desktop 3D printers (20–50 $/kg). Additionally, large-scale AM machines have a higher material throughput on the order of 50 kg/h. This enables the cost-efficient tool production for several industries. Large-scale 3D-printed tooling will be computerized numerical control (CNC)-machined and -coated, to provide a surface suitable for demolding the composite parts. This paper outlines research undertaken to review and improve the adhesion of the coating systems to large, low-cost AM composite tooling, for marine or infrastructure composite applications. Lower cost tooling systems typically have a lower dimensional accuracy and thermal operating requirements than might be required for aerospace tooling. As such, they can use lower cost commodity grade thermoplastics. The polymer systems explored in the study included polypropylene (PP), styrene-maleic anhydride (SMA), and polylactic acid (PLA). Bio-based filler materials were used to reduce cost and increase the strength and stiffness of the material. Fillers used in the study included wood flour, at 30% by weight and spray-dried cellulose nano-fibrils, at 20% by weight. Applicable adhesion of the coating was achieved with PP, after surface treatment, and untreated SMA and PLA showed desirable coating adhesion results. PLA wood-filled composites offered the best properties for the desired application and, furthermore, they have environment-friendly advantages.

TiOxCy Thin Film Deposition by CO2+-Ion Beam Sputtering of Titanium

1993 ◽  
Vol 316 ◽  
Author(s):  
BERTILO E. KEMPF
Keyword(s):  
Near Infrared ◽  
Ion Beam ◽  
Thin Film Deposition ◽  
Ion Source ◽  
Film Deposition ◽  
Refractive Indices ◽  
Ion Beam Sputtering ◽  
Infrared Wavelength ◽  
Beam Sputtering ◽  
Current Densities

ABSTRACTTitanium metal is sputtered by ion beams using a Kaufman-type ion source with carbondioxide as working gas. Deposition takes place on watercooled substrates of silicon and InP. The films obtained are amorphous; they adhere excellently. SEM-pictures reveal a featureless dense fracture and a smooth surface. Despite a carbon content of 9 at % the films are highly transparent in the visible and near infrared wavelength range. Refractive indices center around 2.15 at values typically found for amorphous TiO2. The electrical properties are characterized by dielectric constant of ε = 26 ± 3, leakage current densities at breakdown of jL = 3.65 . 10-3 A/cm2 and breakdown fields EB > 1 MeV/cm.

The pressure dependence of refractivity of polar gases

1960 ◽  
Vol 255 (1282) ◽  
pp. 427-433 ◽  
Keyword(s):  
Pressure Dependence ◽  
Sulphur Dioxide ◽  
Experimental Error ◽  
Methyl Chloride ◽  
Molecular Polarizability ◽  
Refractive Indices ◽  
Methyl Fluoride ◽  
Carbon Tetrafluoride ◽  
First Order

The refractive indices of several gases have been measured at varying pressures in the range 0 to 50 cm. For carbon tetrafluoride, methyl fluoride and methyl chloride the refractivity varies directly with the density within the limits of experimental error. For ammonia and sulphur dioxide the increase of refractivity with pressure is less than would correspond to the increase in density. This may be interpreted in terms of a negative ‘first-order hyperpolarizability' for the polar vapours, whose molecular polarizability is being decreased by the influence of the field due to neighbouring molecular dipoles.

The refractive indices and Verdet constants of the inert gases

1960 ◽  
Vol 259 (1298) ◽  
pp. 424-431 ◽  
Keyword(s):  
Experimental Data ◽  
Refractive Index ◽  
Atomic Hydrogen ◽  
Experimental Error ◽  
Atomic System ◽  
Inert Gases ◽  
Refractive Indices ◽  
Verdet Constant

A method is suggested by which the refractive index and Verdet constant of an atomic system may be derived theoretically. It is applied to atomic hydrogen and to the inert gases and a comparison is made with experimental data. The Verdet constant of neon is not anomalous. The origin of the suggestion appears to be an underestimate of the experimental error. The analysis yields values of th e polarizabilities of th e inert gases which are respectively He, 1-384; Ne, 2-663; Ar, 11-080; K r, 16-734; X e, 27-292 in units of α 3 0

scholarly journals Effect of 3D Printing Parameters on the Refractive Index, Attenuation Coefficient, and Birefringence of Plastics in Terahertz Range

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Alexander T. Clark ◽  
John F. Federici ◽  
Ian Gatley
Keyword(s):  
Refractive Index ◽  
3D Printing ◽  
Attenuation Coefficient ◽  
Refractive Indices ◽  
Attenuation Coefficients ◽  
Layer Height ◽  
Nozzle Size ◽  
3D Printed ◽  
Printing Parameters ◽  
Real Refractive Index

The refractive indices, attenuation coefficients, and level of birefringence of various 3D printing plastics may change depending on the printing parameters. Transmission terahertz time-domain spectroscopy was used to look for such effects in Copolyester (CPE), Nylon, Polycarbonate (PC), Polylactic acid, and Polypropylene. The thickness of each sample was measured using an external reference structure and time-of-flight measurements. The parameters varied were printer nozzle size, print layer height, and print orientation. Comparison of these parameters showed that a printer’s nozzle size and print layer height caused no change in real refractive index or attenuation coefficient. A change in printing orientation from vertical to horizontal caused an increase both in real refractive index and in attenuation coefficient. In vertically printed samples, the increase in birefringence was proportional to the increase in layer height and inversely proportional to nozzle size. There was no measurable intrinsic birefringence in the horizontally printed samples. These effects should be taken into account in the design of FDM 3D printed structures that demand tailored refractive indices and attenuation coefficients, while also providing a foundation for nondestructive evaluation of FDM 3D printed objects and structures.

On the development of low cost, optimizable, 3D printed turbine flow meters for pipe and open channel applications

2020 ◽  
Author(s):  
Adrian Butler ◽  
Tom Rowan ◽  
Alex Colyer
Keyword(s):  
Open Channel ◽  
Lower Cost ◽  
Low Cost ◽  
Flow Meters ◽  
Skill Sets ◽  
Know How ◽  
3D Printers ◽  
3D Printed ◽  
Further Development ◽  
Turbine Flow Meter

<div> <p>The work sets out a method and evaluates the accuracy of a 3D printed turbine flow meter for open channel and pipe flow; that can be optimised for different situations.  The motivation for this project was to create flow meters that are low cost and available to community groups and interested individuals, this work was conducted as part of the CAMELLIA project (Community Water Management for a Liveable London).  The flowmeters have been trialled in a number of locations by users with different skill sets and technical know-how.  Hall effect sensors have been coupled with consumer grade electronics to develop the most opensource system possible.  This work has taken advantage of recent advances in DLP printing, allowing for greater resolution at a lower cost than previous generations of 3D printers.  This is combined with work developed by the Open Prop software team, has enabled user customisable sensors to be built.  </p> </div><div> <p>The presented work aims to create an opensource, low cost and easy to use solution to some flow monitoring problems.  This paper details the lessons learnt and successes of this approach; it aims to create a basis for which further development and deployment of these sensors can be achieved.  </p> </div>

scholarly journals Immersion Factor of In-Water Radiance Sensors: Assessment for a Class of Radiometers

2006 ◽  
Vol 23 (2) ◽  
pp. 302-313 ◽  
Author(s):  
Giuseppe Zibordi
Keyword(s):  
Seawater Temperature ◽  
Fused Silica ◽  
Field Of View ◽  
Refractive Indices ◽  
Specific Class ◽  
Optical Components ◽  
Optical Window ◽  
Sensor Model ◽  
Half Angle ◽  
The Relationship

Abstract The spectral immersion factor of in-water radiance sensors If quantifies the effects of changes in the sensor's response when operated in water versus in air. The values of If are currently computed with a relationship derived from a basic sensor model, which only requires knowledge of the refractive indices of the water and the material constituting the sensor's optical window in contact herewith. Uncertainties in the computation of If are investigated in the 400–700-nm spectral range for a specific class of widely used multispectral radiometers. The analysis is made by comparing If values from the theoretical relationship currently in use with (i) If from a new relationship based on an extended sensor model accounting for the actual solid-angle field of view and the reflectance and transmittance of the external and internal optical components, and (ii) experimental If determined with sample radiometers having diverse optical windows made of materials with different refractive indices. Results highlight that the relationship derived from the basic sensor model introduces a 0.4% negative bias when applied to the considered class of radiometers having a fused silica optical window, a 13° in-air half-angle field of view, and an estimated detector reflectance of 0.15. Reference values of If for the specific class of radiometers, determined with the newly proposed relationship, are presented, and their dependence on seawater temperature and salinity is discussed.

Sign in / Sign up

Export Citation Format

Share Document